Energy generating system

ABSTRACT

A system ( 1 ) designed to generate energy with the aid of, primarily, sea currents, comprising a rotation body ( 4 ) having a front inlet side ( 2 ) and a rear outlet side ( 3 ), and at least one transfer member ( 6 ) connected between the inlet side ( 2 ) and a generator ( 5 ). The rotation body has a conical and/or bulb shaped, tapering section ( 8, 9 ) extending from a substantially cylindrical waist section ( 7 ) in direction towards the inlet side, and a conical and/or concave or flat portion extending in the opposite direction from the outlet side, said waist section being along its circumference provided with close to each other mounted blades ( 10 ) for the purpose of maintaining a rotation of the rotation body, the free, front end of which is at the same time secured to the transfer member ( 6 ) in order to transfer a rotational movement to the generator ( 5 ).

The present invention relates to a system for generating energy,primarily with the aid of sea currents, and comprising a rotation bodyhaving a front inlet side and a rear outlet side, and at least onetransfer member connecting the inlet side with the generator.

The prior art methods and systems intended to generate energy with theaid of i.e. sea water have turned out to require high costs. Also, theirefficiency has been low inter alias because the energy generated withuse of those systems has often been insufficient with regard to theinvestment costs.

The object of the present invention is to establish a system forgenerating energy with the aid of, primarily, sea water current. Itcomprises a rotation body allowing production of significantly moreenergy than the amount previously possible to create. Thanks to theflexibility of this system it can be located in such places in the seawhere the sea currents are strongest. The features characterizing theinvention are set out in the claims.

Thanks to the invention there has now been provided a system which in anexcellent way satisfies the purposes. Also, it can be manufacturedconveniently and at a relatively low cost. According to the inventionthe system comprises a rotation body which constitutes the core of theinvention and which is brought to rotate by the sea currents in whichthe system is localized.

The rotation of the rotation body can be optimized by adjustment of theangles of the blades which are oriented around the waist portion of therotation body. The rotation body is retained in its level in the seawith the aid of transfer members which also transfer the rotationmovement to a generator. Due to the special shape of the rotation bodyvery high efficiency is obtained relating to the conversion of slowflows consisting of a large water volume. The transfer of the rotationof energy from the rotation body takes place by means of the transfermember to a generator, either for direct transfer of generated electricenergy or for storing of that energy. The system includes a pump or acompressor which keeps the rotation body in the correct power generationposition in combination with the blades on the circumference of thebody. Said pump or compressor is used to adjust the degree to which therotation body is filled with i.e. water which does per se influence therotation position of the body in the sea. In order to eliminate thefriction of the fluid which is inside the rotation body and determineits filling degree the inner side of the rotation body is provided withinternally oriented blades which cause the fluid inside to rotatetogether with the rotation body instead of creating a friction againstits inner walls. This arrangement means that the blades do also functionas ribs making all of the rotation body more rigid.

Some preferred embodiments of the invention are described below withreference to the drawings.

FIG. 1 is a diagrammatic lateral view showing a system according to thepresent invention,

FIG. 2 illustrates an alternative way to use the system according to theinvention,

FIG. 3 is a diagrammatic, cross sectional lateral view showing arotation body included in the system according to the invention androtationally supported inside a nozzle-like, surrounding casing,

FIG. 4 is an end view of the rotation body and its casing according toFIG. 3,

FIG. 5 is a diagrammatic lateral view of another embodiment of theinvention showing a rotation body having a front inlet side with aconical portion and an outlet side with a flat portion,

FIG. 6 is a diagrammatic view showing a rotation body included in thesystem and illustrating how the height position of the rotation body canbe varied by variation of the filling degree of the rotation body,

FIG. 7 is a cross sectional view through the waist portion as seentowards its inlet side and illustrating the internal blades,

FIG. 8 a–8 d illustrate different designs of the inlet and outlet sidesof the rotation body, also showing the axial and radial location of theblades at the waist portion of the body,

FIG. 9 a–9 dillustrate possible designs of the water inlet and outletside, respectively,

FIG. 10 is a diagrammatic lateral view showing a pivotably transferringmember for the rotating movement, which eliminates the influence of thewave movements,

FIG. 11 shows a rigid, radial force transfer with the aid of a transfermember including a pivotably coupling and a current and an electriccurrent generator mounted inside the body, the transfer member beingconstituted by a rigid transfer shaft,

FIG. 12 is a lateral view showing another embodiment according to whichthe rotation body does around its waist portion exhibit a truncatedconical body, the oblique lateral surfaces which converge towards thewaist portion and emerge therein via blades or wings around the waistportion which are located at a predetermined distance from each other,

FIG. 13 is an end view of the rotation body showed in FIG. 12,

FIG. 14 does diagrammatically show a rotation body according to theinvention and illustrates how the currents are concentrated.

As appears from the drawing figures the invention is constituted by asystem 1 for producing energy with the aid of, primarily, sea currentsand comprising a rotation body 4 having a front inlet side 2 and a rearoutlet side 3 as well as at least one transfer member 6 connecting theinlet side 2 with a generator 5. The transfer member 6 can beconstituted by either a flexible or a rigid shaft.

The rotation body 4 (or 4′, 4″, 4′″) exhibits a tapered portion 8 (or8′, 8″, 8′″) extending from a substantially cylindrical waist portion 7(or 7′, 7″, 7′″) towards the inlet side 2 and being conical and/orbulb-shaped. The different shapes of the rotation body 4 (or 4′, 4″,4′″) at the inlet side 2 and at the outlet side 3, respectively, areshown more in detail in FIGS. 8 a–8 d and 9 a–9 d. The bulb shape, thetunnel shape, as well as the axial and radial location of the bladesmaking the body 4 (or 4′, 4″, 4′″) rotate are designed to match thefactors determined by the average flow, the average temperature and thesalt content and which have been individually calculated for eachselected mounting position. At the rotation body 4 (or 4′, 4″, 4′″) thestreams are concentrated to its outer diameter after which they convergeto their original shape. For that reason the blade height is calculatedin consideration of that fact. Suitable outlet shapes of the rotationbody 4 (or 4′, 4″, 4′″) are shown in FIGS. 8 a–8 d and 9 a–9 d. Theshapes have been selected to create a maximum efficiency in order tomatch the combined influence of different density, salt content andcurrent flow speed variations.

The rotation body 4 does around its waist portion 7 exhibit blades 10interspaced at different distances and functioning to maintain therotation of the rotation body. The free, front end of the rotation body4 is connected to the transfer member 6 for the purpose of transferringa rotation movement to the generator 5. The blades 10 can haveadjustable attack angles so that they can be turned to yield the highestpossible output power.

According to an alternative embodiment, more in detail shown in FIGS. 12and 13, the waist portion 7 of the rotation body exhibits a truncated,conical body 26 supported by blades or wings 10. Its converging sides27, 28 are facing the waist portion 7 so as to create a tunnel-likeformation 29 catching the sea currents and directing towards the blades10 through the intermediate bases 30. According to the preferredembodiment the mounting angle of the blades 10 can be about 45°. Thepower obtainable thanks to the rotation of the rotation body can in thatcase be increased by about 30%.

For the orientation of the rotation body 4 in the sea the lattercomprises a fluid supply member 11, consisting of e.g. a pump or acompressor, which keeps the body in the correct power-consuming positionin combination with the above mentioned possibilities to vary the bladeangle at the intensity of the sea currents. In order further to increasethe effectiveness of the rotation body the latter can be mounted in anozzle-like casing 12 which could be shaped like a hour-glass and thewalls of which diverge from the tapered center section 13 of the casingin which the rotation body is rotatably supported in bearings 14 whichare secured to the inlet 15 and the outlet 16, respectively, of thecasing 12. According to the embodiment shown casing 12 has a squarecross section providing a larger area as compared with a circular crosssection and, consequently, a maximum flow speed which in its turn to therotation body 4 imparts the highest possible rotation movement.

The external wall 17 of the rotation body 4 does on its inner surfacehave blades 18 around the circumference for the purpose of eliminatingthe friction generated by a fluid, for example water, which is presentinside the rotation body 4. At the same time blades 18 serve as ribswhich make the outer wall 17 of the rotation body 4 stiffer. Thanks tothis arrangement the water filling up the interior of the rotation body4 will participate in the rotation movement.

FIG. 1 illustrates how a system 1 according to the invention can bedesigned. In this case system 1 comprises an anchor member 20 which isresting on the sea bottom and from which extends a chain 21 connected toa float member 22 which in its turn supports an accumulator 23 for thepurpose of storing energy from the rotation body 4 via the transfermember 6 and the generator 5. Connected to the float member 22 is also acable 24 which when desired can be used to transport energy to theshore. Another possibility is to transfer the energy stored in theaccumulator 23 to different types of collection ships for continuedtransport of the stored energy to the desired destination.

FIG. 2 does diagrammatically show a system 1 according to the inventionin which the rotation body 4 is supported in a sea current with the aidof an anchoring member 20 provided with a frame 25. The latter helps tokeep the rotation body 4 in a predetermined position in the sea current.The transfer member is pivotably connected to frame 25 to which is alsoconnected a cable 24 for the purpose of transporting energy to land.

FIGS. 10 and 11 do in the system 1 according to the invention illustratedifferent connections between the rotation bodies 4 and the floatmembers 22. FIG. 10 illustrates an articulated power transfer whicheliminates influence from the sea waves. FIG. 11 illustrates a stiffradial connection including an articulated coupling and an electriccurrent generator 5 installed inside the rotation body 4. There is alsoa cable which transports the energy generated in the generator 5 throughthe transfer member 6, in this case constituted by a rigid shaft.

The difference structures above described have made it possible tocreate a system including a rotation body the circumferential speed ofwhich can be increased radially. The low flow and the great amount ofwater can be concentrated to an added force at the circumference.

FIG. 14 does diagrammatically show how the streams get concentrated tothe outer diameter of the rotation body 4, especially in the waistportion 7 area. Following this the streams are again united to theiroriginal shape. For that reason the blade size has been calculated tomatch exactly this fact and there has been attained an efficiencycorresponding to about 16 kW/m² which is four times more than accordingto the prior art solutions.

1. System (1) for generating energy, primarily with the use of seacurrents, comprising a rotation body (4) having a front inlet side (2)and a rear outlet side (3), and at least one transfer member (6) betweenthe inlet side (2) and a generator (5), wherein said rotation body has aconical and/or concave section extending in a direction toward theoutlet side as well as a conically and/or bulb shaped tapering portion(8, 9) extending from a substantially cylindrical waist portion (7)towards the inlet side, wherein the waist portion is provided withturbine blades (10) only along its circumference that are adapted tomaintain the rotation of the rotation body, a free front end of which issecured to the transfer member (6) to transfer a rotational movement tothe generator (5), and wherein an inner surface of an outer wall (17) ofthe rotation body (4) exhibits blades (18) along its circumference forthe purpose of eliminating friction generated by a fluid (19) inside therotation body.
 2. System according to claim 1, characterized in that theincidence angles of the turbine blades (10) are variable.
 3. Systemaccording to claim 1, characterized in that the rotation body (4)comprises a fluid supply member (11) adapted to keep the body in acorrect float position in response to the intensity of the sea currents.4. System according to claim 1, characterized in that the rotation body(4) is located inside a nozzle-like casing (12) having a substantiallyhour-glass form, its walls diverging from the tapered central section(13) of the casing (12) in which the rotation body (4) is rotatablymounted.
 5. System according to claim 3, characterized in that a casinghas a square cross section.
 6. System according to claim 1,characterized in that said blades (18) further serve as ribs for thepurpose of stiffening up the outer wall (17).
 7. System according toclaim 1, characterized in that the waist portion (7) of the rotationbody (4) exhibits a truncated, conical body (26) supported by theturbine blades (10) and extending around the waist portion, theconverging sides (27, 28) of said conical body facing the waist portion(7) to form a tunnel formation (29) defined by the tapering portion (8,9) of the rotation body and by the front side (27) of the truncated body(26) and narrowing towards the turbine blades (10) and between existingintermediate spaces (30) between said turbine blades (10) for thepurpose of collecting and directing the sea currents.